Polymeric binder of polyacrylic acid, polyfunctional amine, and linking benzene ring

A negative electrode for a power storage device, comprising:

• a current collector made of a metal material;
• and
• a negative electrode active substance layer bonded onto the current collector, wherein
• the negative electrode active substance layer contains a negative electrode binder for bonding the negative electrode active substance to the current collector, and
• a polymer compound to be used as the negative electrode binder
• a polymer compound to be used as the negative electrode binder comprises a chain structure constituted of a polyacrylic acid and a crosslinked structure connecting carboxylic acid side chains in the chain structure or between the chain structures, and
• the crosslinked structure is a crosslinked structure represented in the following general formula (6), where PAA is a chain structure constituted of a polyacrylic acid, X is a ring structure having 1 to 3 benzene rings, and C1 to C4 are each a carbon atom constituting a benzene ring in the ring structure